Metal working tool



May 11, 1965 E. D. BILLING 3,182,475

l METAL WORKING TooL Filed Dec. 27. 1960 2 sheets-sheet 1 JNVENTo BY Elmer D. D| |I|ng May 11, 1965 Filed DSG. 27. 1960 E. D. D|LL|NG METAL woRKniG TOOL 2 Sheets-Sheet 2 INVENToR. Elmer D. Dilling BY gm Agent United States Patent O 3,182,475 METAL WORKNG T901,

Elmer D. Billing, Las Vegas, Nev., assigner to Titanium Metals Corporation of America, New York, NSY., a corporation of Delaware Filed Dec. 27,1960, Ser. No. 78,469 10 Claims.v (Cl. 72-77) This invention relates to a tool for working metal and more particularly to a tool useful in the metal working operation known in the art as dow-turning.

Flow-turning, or spin forging as it is sometimes referred to, is a relatively new development in the metal working ait. In flow-turning a blank such as a ring or heavy section tube is arranged on a mandrel or other support body of exterior configuration corresponding to that desired for the interior surface of the ow turned product. The mandrel with the blank lmounted thereon is then rotated and a tool in the form of a wheel free to turn is pressed against the outer surface of an end of the blank. The metal forming wheel travels around the periphery of the blank and in so doing causes the metal to iiow laterally with respect to the engaging edge of the wheel, that is, generally in the same direction as 4the axis of the forming wheel and along the length of the mandrel. Thus, for example, a thick walled tube blank can be placed on a cylindrical mandrel closely fitting the interior dimension of the tube blank, and can be flow-turned to form a tube of thinner wall thickness, and corresponding by increased length, than the original tube blank.

In flow-turning operations as heretofore carried out, the pressures to be exerted by the forming wheel are generally considerable in order to force the metal to flow as desired. The organization is often arranged with a pair ot' wheels one on each side of the workpiece so that the forces exerted will be generally against each other. However, whenever an outer edge of a working wheel is pressed against the convex surface of a tubular or cylindrical workpiece there is a tendency for the workpiece and mandrel to spring away from the wheel, or sidewise from between the wheels if an opposed pair are employed. Therefore, the supporting and rotating mechanisms must be heavy and relatively inflexible requiring generally large, strong and expensive structures.

It is therefore the principal object of this invention to provide an improved metal working tool adapted for flow-turning. Another object of this invention is to provide a compact and simple flow-turning tool. Still another )object of thi-s invention is to provide a more ecient metal flow working tool. Yet a further object of this invention is to provide a how-turning tool in which the metal working elements are contained in a compact organization requiring no auxiliary wheel shafts andassociated mechanism. These and other objects of this invention will be apparent from the following description thereof and from the annexed drawings in which:

FIG. 1 shows a general side view of a flow-turning tool embodying features of this invention.

FIG. 2 shows a section view ofthe tool of FIG. 1 taken along the line 2-2.

FIG. 3 shows a cross section of the tool of FIG. 1 taken along the line 3-3.

FIG. 4 shows a modication of the` general tool design of FIG. 1.

FIG. 5 shows a sectional view of the tool of FIG. 4 taken along the line 5-f5.

FIG. 6 illustrates the tool of FIG. 4 in operation as it would be employed to flow-turn a tubular blank to form an elongated tube of reduced wall thickness.

FIG. 7 is a detailed and sectional view showing particularly the tube blank as it passes through the tool and being reduced in wall thickness in the organization of FIG. 6.

ICC

Referring now particularly to FIGS. l, 2 and 3, the tool 9 comprises an outer frame indicated at 11 which in this embodiment is of generally rectangular shape formed by ends 12 and sides 14. Adjustably mounted in side by side or parallel relationship in outer frame 11 are inner frames 16. Adjustability of inner frames 16 is arranged by provision on their opposite sides of V-shaped projections or tongues 18 which engage corresponding V-shaped parallel grooves 20 in the interior faces of outer frame sides 14. It will be seen that inner frames 16 are thus guided in a lateral direction and they may be set in any desired adjustment in this direction by provision of locking screws 22 which bear against the ends of inner frame members 16 and which are threaded through outer frame ends 12 as at 24. After setting the desired adjustment by appropriate rotation of screws 22, they may be locked in their set relationship by tightening locking nuts 25. Interior frames 16 are provided with central bores as at 28 and freely rotatably mounted in bores 28 are working rings 30. The inner edges 31 of working rings 30 are of blunt cross section and may be rounded as shown so that they are adapted to flow-turn a work-piece against which they are pressed during rotation of tool 9 around such workpiece. Free rotation of working rings 30 with respect to bores 28 of inner frames 16 may be insured by provision in each of a suitable bearing such as interposed ball bearing assembly 32 which is composed of an outer race 34, bearing balls 36 and inner race 33. The respective dimensions of the bores 28, ball bearing assemblies 32 and working rings 36 may be arranged so that the outer surface of outer races 34 form press ts with the surfaces 'of bores 28 and the outer surfaces of working rings 30 form press tits with the inner surfaces of inner ball bearings races 33.

In the modiiication of this invention illustrated as 39 in FIGS. 4 and 5, an annular or ring type outer frame is employed and relative adjustment of the working rings with respect to each other is obtained by double eccentric organizations. Referring now to FIGS. 4 and 5, a heavy annular outer frame 40 is provided with apair of partial bores 42 and 44 which are drilled or otherwise formed in opposite sides of outer frame 40, and which are eccentric with respect to frame 40, and the eccentricity of these partial bores 42 and 44 is diametrically opposite one to the other. Adjustably mounted in bores 42 and 44 are annular inner frames in the form lof rings 45 which are characterized by eccentric bores 48. Annular inner frames 46 may be rotated inside bores 42 and 44 to adjust their relative positions, and when set as desired may be maintained in such adjustment by locking means such as set screws 50 set in from the outer edge of outer frame 40.

Mounted in inner frame bores 48, as by a press t, are bearing assemblies 52 composed of outer races 54, inner races 56 and interposed bearing balls 58. Mounted in the inner races 55 of bearing assemblies 52 are working rings 6? and these may also be conveniently assembled by a press fit. The inner edges 61 of working rings 50 are also of blunt cross section, partially tlattened, adapted to iiow-turn a workpiece against which they are pressed during rotation of tool 39 around such workpiece. Preferably the internal side edges of inner races 55 are bevelled as at 62 to engage corresponding shoulders 64 protruding from adjacent edges of working rings 6G.

Flat cover rings 66 are provided to maintain inner frames 45, bearings 52 and working rings 69 in their proper adjusted relationship. These are firmly attached to the opposite sides of outer frame 40 by means of boits 68.

Thus, it will be seen that working rings 6G may be ad# justed and locked in adjusted position so that the same working ring relationship may be obtained as is obtainable with the embodiment illustrated-in FIGS. l, 2 and 3.

In operation, the device of this invention may be employed, for example, to reduce the wall thickness of a relatively thick walled tube blank with corresponding increase in length of the tube. Any suitable apparatus may be employed which imparts rotary motion to the device around the blank which is mounted on a mandrel.l FIGS. 6 and 7 illustrate a simple and basic method in which a lathe is utilized, it being understood that for heavy work, that is, working large'diameter and thick wall blanks and making large reductions in a single pass, heavier and more powerful machines will be required and suchmachines themselves may be of conventional design or of such design'readily adapted for the lpurpose by those skilled in the art.

In FIG. 6 a more or less conventional lathe is employed having a bed or base 70 on which are mounted ways 72. At an end of base 70 is mounted head stock 74 which contains lor has associated therewith a suitable motor `(not shown) `for rotating its face plate 76 to which is attached, as by clamping dogs 78, a tool 39 which, by wayl of example, is the tool illustrated in FIGS. 4 and 5.

At the other end of base 70 is tail stock 80 on which is mounted .tail stock chuck 82 in which is'chucked and held rm the end of an elongated cylindrical mandrel 8d. The other end of mandrel 84 passes throughy tool 39 and a suitable central aperture in face plate 76.

Slidably mounted on ways 72 is carriage 86' which is driven back 'and forth along Ways 72 in conventional man- 'ner by rotation of lead screw 88 which is in turn actuated 4by a suitable connection to the headstock spindle. Fixedly attached to carriage S6 is pillow block mounting member 90 into which is placed on end of tube blank 92 as a workpiece and which has been mounted 'on mandrel Sd. The upper and lower segments of mounting member l90 are iirmly fastened around one end of tube blank 92 as by tightening hold down boltsl 94. The other end" of tube blank 92 is placed at the mouth of the adjacent working ring in tool 39.

FIG. 17 illustrates the adjustment of the working'ringsk inner edge 61a or actual forming part, has its side closesty to the center of the tool spaced from the tool center a dis- 4 and 5 is convenlent for centering yanddrivmg ,1n a lathe-` tance equal to one' half the outside Vdiameterof the tube l after the desired preliminary wall reducing step. The other working ring specifically identifiedas b'is adjusted so that the; side of its inner edge 61'b closest to the center of the tool 39 is spaced from said center one half the outside diameter of the tube it is desired to nallyrproduce. It will be seen that the preliminary wall thickness reduction shouldbe about one half the total reduction. Also,

these working rings are adjusted so that these closest sides are diametrically opposite to each other, or as close to opposite as can ordinarily or reasonably be attained.

Now with the working rings adjusted as described, the

tube blank 92 is fed into the tool 39 by action of carriage f 86 pushing it in the direction of the arows on FIG. 7. At the same time the tool 39 is rotated about its center,.and the close sides of working rings 60a and 60b progressively press into the metal of tube blank 92 as they travel around it. Thus, the metal of the tube blank 92 is squeezed between the working ring edge and the supporting mandrel and is reduced ink wall thickness in the two step working process, .and at the same time the tube is correspondingly elongated. sion may be applied over the workpiece to promote working of the metal and elongation during working and wall thickness reduction.

` The working action of the tool of this invention is different from many heretofore widely practiced forming operations. It must be understood that the metal of the workpiece, as it is worked under the conditions described, is caused to ow in a direction parallel to the long axis of If desired longitudinal tenthe tube blank and essentially ata right angle to the principal direction of the pressure applied by the working rings. This ocurs because the carriage 86 is forcing the tube blank into the working rings 60a and Gibb, as seen in FIG.'7, at the same time` that these rings are vworking the metal between each of them and the mandrel as they metal is worked out into a tube of desired thinner wall.

thickness and corresponding increasedl length.

The embodiment of thisinvention.illustrated in FIGS.

like machine. The tool should generally-be rotated at a speed of several hundred revolutions per yminute and the annular or ring type frame andr general assembly described may be easily balanced and adapted for Vthis type ot4 service. carriage by meansof mounting member 90'insures that the tube blank itself will'not rotate and at the same time can be fed at the desired speed into the working rings. On

lthe other hand, it will be appreciated that the .equivalent effect can be obtained by clamping the tool'stationary and rotating the tube blank, yand the: mandrel on which it is mounted,` if this is convenient. The embodiment of this invention shown in FIGS. '1, 2 and 3 is readily adapted for such application and canjbe Vconveniently secured while suitable machinery for rotating and feeding the tube blank may ybearanged by those skilled in the art. The embodiment of the tool shown in FIGS. 1, Zand 3 is somewhat simpler and less expensive to construct than the modification illustrated, in FIGS. 4 and 5 but is not so readily centered and mounted for high 'speed rotation.

The tool of' this invention may be provided with one or a plurality of working rings. If one yring is employed, the supporting and driving structure during operation must be strong and Vrigid to withstand the one-sided force exerted. The embodiments illustratedy in which a `pair of working rings are employed at diametrically opposite positions about the center has thel advantage of `balancing the working forces exerted bythe working rings to a large extent. It will'be appreciated that since the rings are not in the same plane, these forces will not be precisely balanced. However, withr the tube blank'mounted on a rigidmandrel and with reasonably close lateral spacing between the working rings, .a very effective and practical balance can be obtained in the unit.- The number and setting of ythe working ringswill be, toa large extent, determined by `the type of metaly being worked and the degree of reduction desired. Soft andv ductile metals such as copper and aluminum can take reductions in wall thickness of up to-50% or more with Vone pass through a single Working ring., The degree of reduction which can ybe appliedto.hardermetals such as stainless steel and` titanium is substantially less, as would be expected. As an example of the .type vof reductions obtainable' a copper tube of 3%; inchinside :diameter and 0.0625 wall thickness was.r employedl as a4 blank and a tool essentially the same as that shown yin FIGS. 4 and 5 was used in a set up as shown in FlGSf and 7.v The tool wasy rotated at 250 r.p.m..and the tube -blank =ad vanced through. the tool at a rateof 0.008 inch, per revolu- Clamping the. endof tube blank 92 to the :gleam/ 5 difficult to form and required a double pass to reduce a 1.25 inch outside diameter titanium tube blank having a' 0.094 inch Wall thickness. The lirst pass reduced the Wall thickness to 0.059 inch. The tool Was reset and the second pass reduced the Wall thickness to 0.043 inch for a total reduction in wall thickness of 54%.

In the embodiments illustrated lthe inner edges of the working rings have been shown as of simple blunt design. Such a blunt Working edge coniiguration may be suitably rnodied or varied to adapt it for specific applications. Thus the working edge may be more or less blunt, and may be rounded, flattened, angled or even stepped to obtain desired metal flow and displacement during flow-turning. p

The tool of this invention has a number of unique advantages. Working the metal with the internal edge of a ring provides a vsubstantially longer line of contact than can be obtained using the external surface of a wheel, where the contact is more nearly that of a point. Therefore, metal displacement laterally (with respect to the tube blank) is more restricted, and more etlicient metal iloW longitudinally out from under the wheel at right angles .thereto is obtained. Also the working portion of the inner edge of the ring is concave with respect to its contact with the tube blank instead of convex as is the working edge of a wheel, and this fact also, it is believed, assists materially to obtain the eiiicient working action, andpoperating stability.

The tool is also compact and the outer frame contains and maintainsthe working rings in adjustment and in position for work. Whenworking wheels are employed jack shafts or other auxiliary mounting and power transferringmechanisms must be employed and these must be individually adjusted and set to obtain the desired metal working result. The mountings and machinery in general must be heavy and rigid. Employment of Working rings, however, according to this invention, enables these to be placed inside a strong frame where their position is maintained by encircling their outer surfaces as in a raceway, instead of by an axial shaft. Thus, much more rigid adjustment and alignment can be maintained.

The tool of this invention is useful to produce thin wall metal tubing from a tube blank of substantially greater wall thickness and a shorter length. lf desired, the Wall thickness of the product tube may be varied over its length by appropriate intermittent or continuous adjustment of the working ring settings. Thus, the outside diameter of the finished tube may be made thinner or thicker in certain locations as desired. A tube length having a thinner wall thickness at its center compared to its ends has certain structural advantages and such tubing may be produced by suitable adjustment of the working rings along the tube length as it is worked out. By employing a mandrel with a reduced diameter portion and Working the tube blank down over this reduced diameter portion of the mandrel, the tool of this invention can also produce a sink or reduction in inside diameter of the tube blank. When operating under these conditions the wall thickness reduction will not be generally as great as when a uniform diameter mandrel is employed.

I claim:

l. A metal working .tool comprising: an outer frame; a plurality of inner frames adjustably mounted in parallel relationship in said outer frame; means for locking said inner frames in set `adjust-ments with respect to said outer frame; and a plurality of working rings freely rotat- V ably mounted one in each of said inner frames, the inner edges of said Working rings being smooth and of blunt cross section and adapted to flow-turn a workpiece against which said edges are rotatively pressed.

2. A metal working tool comprising: a rectangular outer frame having sides with parallel grooves in the inner surfaces thereof; a pair of inner frames adjustably mounted in said outer frame and having tongues slidably engaging the grooves in said outer frame sides;

means for locking said inner frames in set adjustments with respect to said outer frame; and a pair of working rings freely rotatably mounted on in each of said inner frames, the inner edges of said working rings being smooth and of blunt cross section and adapted to dowturn a workpiece against which said edges are rotatively pressed.

3. A metal working tool comprising: a rectangular outer frame'having sides with parallel grooves in the inner surfaces thereof; a pair of inner frames adjustably mounted in said outer frame and having tongues slidably engaging the grooves in said outer frame sides; means for transflxing the ends of said outer frame and bearing against ends of said inner frames for locking said inner frames in set adjustments with respect to said outer frame; and a pair of Working rings freely rotatably mounted one in each of said inner frames, the inner edges of said working rings being'smooth and of blunt cross section and adapted to dow-turn a workpiece against which said edges are rotatively pressed.

4. A metal Working tool comprising: an annular outer frame having a pair of eccentric partim bores, one in each of the opposite sides thereof, with the eccentricity of said partial bores being diametrically opposite one to the other; annular inner frames, each having an' eccentric bore, adjustably rotatably mounted in said partial bores; means for locking said inner frames in set adjustments with respect to said outer frames; and a pair of working rings freely rotatably mounted one in each of thebores in said inner frames, the inner edges of said working rings being smooth and of blunt crosssection and adapted to flow-turn a workpiece against which said edges are rotatively pressed.

5. A metal working tool comprising; an annular outer frame having a pair of eccentric partial bores, one in each of the opposite sides thereof, with the eccentricity of said partial bores being diametrically opposite one to the other; annular inner frames, each having an eccentric bore, adjustably rotatably mounted in said partial bores; means for transiixing the edge of said outer frame and bearing against the outer edges of said inner frames, thereby locking said inner frames in set adjustment with respect to said outer frame; perforated cover plates attached to the sides of said outer frame and enclosing the said inner frames within the partial bores in the sides of said outer frame; and a pair of Working rings freely rotatably mounted one in each of the bores in said inner frames, the inner edges of said Working rings being smooth and of blunt cross section and adapted to flowturn a workpiece against which said edges are rotatively pressed.

6. Tube shaping apparatus, comprising: a frame having at least a pair of tube shaping rings rotatably mounted thereon in bearing members individual thereto and relatively adjustable to provide a variable aperture common to said rings for longitudinal passage of a tube therethrough, means supporting said tube for such passage, means for imparting relative rotary and longitudinal movement of said frame with respect to said tube, the adjusting means for said bearing members being adapted for pressing arcuate portions of said rings, respectively, against opposed portions of said tube with counterbalancing forces such as to cause said rings sectionally to reduce said tube and axially to elongate the same during passage of said tube through said rings.

7. Tube shaping apparatus, comprising: a frame having at least a pair of tube shaping rings rotatably mounted thereon in bearing members individual thereto and relatively adjustable to provide a Variable aperture common to said rings for longitudinal passage of a tube therethrough, means supporting said tube for such passage, a mandrel adapted to tit within said tube and mounting means for disposing the same therein, means for imparting relative rotary and longitudinal movement of said frame with respect to said tube and mandrel, the adjusting means for said bearing members being adapted for pressing concavely arcuate portions of said rings, respectively, against opposed portions of `said tube with counterbalancingforcessuch as tojcause said rings sec- .tionallyqto reduce said tube and axially to elongate the same during passage of said tube through said rings.

8. Tube shaping apparatus, comprising: a rotatably mounted Vframe having at least a pair of tube shaping -rings rotatably mounted thereon in bearing members individual thereto and relatively adjustable to provide a variable aperture common to said rings for longitudinal passage of a tube therethrough, means supportingrsaid tube for such passage, means for rotating said frame and for concurrently feeding said tube through said common ring aperture, the adjusting meansfor said bearing members lbeing adaptedfor pressing arcuate portions of said rings, respectively,` against opposed portions of said tube with counterbalancing forces such as to cause said rings during said feeding sectionally to reduce said tube and axially to elongate the samerduring passage of said tube through said rings. Y

9. Tube shaping apparatus, comprisingzma rotatably mounted frame having atleast a pair of tube shaping rings rotatably mounted thereon in bearing members in-` dividual thereto and relatively adjustable to provide a variable .aperture common to said rings for longitudinal passage of a tube therethrough, meanssupporting said i' tube for such passage, amandrely adapted to twithin said tube and mounting means for disposing thesarne therein,r` means for rotating said frame and for yconcurrently feeding ysaid tube Vthrough saidcommon ring aperture, the adjusting means for said bearing members being j adapted for pressing arcuate portions of said rings, re-

lspectively, against opposed portions Vof said tube with counterbalancing forces such as to` cause saidv rings during saidy feeding sectionally to reduce said tube and axially to elongate the same during passage of said tube through said rings.-k

10. Tube shaping apparatuscomprising: a frame having at least a pair of tube shaping rings rotatably mounted `thereon in bearing membersindividual thereto and relatively adjustable to providea Variable aperture common to said rings for longitudinal passage of a tube therethrough, means supporting said tube for such passage, a mandrel adapted'to fit within said tube and `having a `terminal portion of reduced ,diameter relative to the inner diameter of said tube, mounting means for disposingsaid mandrelwithinsaid tube with said terminal portion in alignment with oneV ofk said tube shapingrings, means for imparting yrelative rotaryV and longitudinal movement of-said frame with respect to'said tube and mandrel, the adjusting means ,for said bearing members Y being adapted for pressing concavely arcuate `portions-of said rings,respectively, against opposed portions ofsaid tube with counterbalancing forces such as to cause said rings sectionally toreduce said tube including'the inner diameter thereof, while axially elongating saidftube, during passage osaid tube through said rings.

References Cited by the Examiner;

WILLIAM- In. STEPHENSON, Priimiary Examiner-. WILLIAM W. DYER, IR., LEON PEAR, Examiners. 

1. A METAL WORKING TOOL COMPRISING: AN OUTER FRAME; A PLURALITY OF INNER FRAME ADJUSTABLY MOUNTED IN PARALLEL RELATIONSHIP IN SAID OUTER FRAME; MEANS FOR LOCKING SAID INNER FRAMES IN SET ADJUSTMENTS WITH RESPECT TO SAID OUTER FRAME; AND A PLURALITY OF WORKING RINGS FREELY ROTATABLY MOUNTED ONE IN EACH OF SAID INNER FRAMES, THE INNER EDGES OF SAID WORKING RINGS BEING SMOOTH AND OF BLUNT CROSS SECTION AND ADAPTED TO FLOW-TURN A WORKPIECE AGAINST WHICH SAID EDGES ARE ROTATIVELY PRESSED. 